Draft hood



K- BOHN DRAFT HOOD Nov. 15, 1932.

Original Filed Oct. 24, 1929 2 Sheets-Sheet l w ma IN VEN TOR.

A TTORNEYS.

Nov. 1 5, 1932.

K. B OHN DRAFT HOOD Original Filed Oct. 24. 1929 2 Sheets-Sheet 2 INVENTOR. BY W A TTORN E YS.

Patented Nov. 15, 1932 KARL BOHN, or us -Em, fiEw YORK DRAFT noon Apphcation filed October 24; 1929, Serial The invention relates to draft hoods and more especially to that type of draft hoods, which are used in connection with the smoke pipes leading from a: furnace equipped with a gasburner to the flue.

By using draft hoods known heretofore, it was necessary to arrange the hood inthe pipe'line'in such a manner, that the hood was standing vertically and this was a great disadvantage especially in cases where furnaces, that-had been equippedwith a heating apparatus for coal or the like, were changed so that they could be heated by means of a gas burner, built into the furnace and replacing the old heating equipment. In such cases the installation of adra'ft hood is an absolute necessity and it occurs frequently that thespace for the arrangement of a hood in vertical position is so small, that it is hardly possible to install said hood.

The object of the present invention therefore is to provide a draft hood overcoming this disadvantage'by being adapted to be installed in the pipe line in any desired angle from the horizontal to the vertical.

Other objects of the invention not specifically mentioned'may be easily ascertained and understood from the following description in Fig. 3 is a sectional view taken on line 3-3 of Fig. .1. f

Fig. 4 is an end view of thehood, seen from that partof said hood which-connects with the flue proper.

The hood accordingto thepresent invention has. like other lmown hoods two tubular or pipe like portions; one of. which 6 connection with the accompanying drawings 7 I m. 462392. awar 1 Angiist' 22","1ea2a" is: adapted to be" connected directly flue. The other pipe like portion 7-;is according to Fig. 1 connected with an elbow 8 from which a pipe line v9E leads to the fife chamber of a furnaoezlO; It ishowever to be understood, that the tubu'larpo'rtionfi may be connected directly with; any kind 02f." a horizontal or vertical part of aa pipe line. communicating with.said fire chamber or with a part of such a pipeline extending in any other angle; Y

Between the two pipe like portions the hood has a frusto-pyramidal body 1-1,@:th'e smaller end whereof is connected tothe tubular portion 6' while the'pipe like portion 7 communicates with the larger end of the body 11. 2

The two tubular portions are arranged: in such a manner, thatthey have a" common axis. Inside of the body 11' a pair of-bafllle plates 12 are arranged in such a manner, that they extend parallel to* a pair of oppositelyafrangedside walls of the body 11 and'th'at they abutwith one of their ends forming a wedgelike body, the apexwhereof is located approximately in the plane in which the first mentioned: tubular portion 6 ends and com 'muni'cates' with the body 'll.

On the larger end of the body 11' and arranged at 'both sides of the tubular pbrtion' 7 two exit channels 13 are provided and the inner sidewalls ofsaid channels" are con 'n'e'cted'with the side walls of portion 14 interposed between the tubular portion' 7 and the pyramid proper. The connecting part between the walls of the channels 13- 'and the connecting part 14 are "preferably shaped semicircular as' indicated at 15 in Figs. 2 and 3.-

On those ends of the bafiie plates" 12px t'ending toward the larger part of thebody 11, a pair of curvedbafile plates 16' are at tached", which abut. with their other ends with each other as indicated at 1 7' Fig-3. The point at which the'setwo curved baflie plates meet is a lso located'on the common I Between the first mentioned baflle plates 12 and the walls of the body 11 extending parallel to said bafile plates another pair of baffles 18 is arranged and extends parallel to said side walls and'is preferably located so that each of said plates is positioned half way between a baffle plate 12and the body 11 extending parallel thereto. 1

The outer wall of each of the two channels 13 may be curved downwardly as indicated at 19 in Figs. 1 and 4. The line on which these curved walls ,join the wall of the body 11' is also the line on which the center point for the semicircular shape of the connecting parts 15 is located and while the hood according to the present invention may be arrangedbetween'the pipe line and the flue at any desired angle, it is to be noted, that this connecting lineshould be kept always as nearly aspossible horizontally for a reason which will appear later on. i The hood accordingto the present invention operates-as follows:

When the furnacelO is being heated the gases of'combustion will travel through the pipe line 9 and the elbow 8 into the tubular portion 7 and through the connecting part 14 into the body 11. When entering the body 11 the gases of combustion will meet an obstacle in the shape of the curved baffle plates 16, so that the draft in the flue, with which the tubular portion 6 communicates cannot exert an overstrong sucking force on said gases of combustion. Said gases will be deflected by the curved bafiie plates 16 and will then flow outwardly through the channels formed by the walls of the pyramid '11 and the baffle plates 12 arranged in the form of a wedge. In this manner the fiameof the burner in the fire chamberof the furnace 10 is protected against the efiects of aniovercold air descending the chimney will not enter the fire chamber, but will be directed directly into the atmosphere. In order to increase the safe action of the baffle plates 12 the additional baffles 18 are arranged and will help to deflect a cold current of air entering-the tubular channels 13.

Having described my invention and how the same is to be performed, I claim as new, and desireto secure by Letters Patent: 1, v 1 A device of=the classdescribed comprising in combination, atubularportion adapted to communicate'with chimney, a second portion 6 toward; the exit tached respectively to the separated ends of said first-named plates.

2. A device of the class described comprising in combination, a tubular portion adapted to communicate with a chimney, a second tubular portion adapted to communicate with a fire chamber of a furnace, and a frusto-pyramidal body arranged between said' tubular portions, and communicating with the same, a pair of exit channels arranged laterally of said second tubular portion and communicating with the larger end of said frusto-pyramidal body, the inner walls of said exit channels being connected with the walls of the second tubular portion by semi circular walls a pair of curved baflle plates having abutting ends, and arranged inside the body, thecurve of said baflle plates being concentricwith the semi-circular walls, a second pairof bafile plates extending parallel to a pair of walls of the frusto-pyramidal body and forming a wedge and being with their separated ends attached respectively to the separated ends of thecurved baffie plates, the

two corresponding pairs of bafi'le plates abutting with each other on lines parallel to each other and to a diameter of the adjacent tubular portions. 7

8. A device of the class described comprising in combination a tubular portion adapted to communicate with a chimney, a second tubular portion adapted to communicate with a fire-chamber of a furnace, and a frustopyramidal body arranged between said tubular portions and communicating therewith, a pair of exit channels arranged laterally of said second tubular portion and communicating with the larger end of the body,

semi-circular walls connecting the inner walls of said channels with the walls of the second tubularportion a pair of curved bafile plates arranged inside the body and having abutting ends, said bafile plates being curved concentrically with the semi-circular walls, the abutting ends of saidplates being located adjacent the second tubular portion, a;pair of plates forming a wedge-shaped baffle, 'the separated ends of said second pair of'plates being attached respectively to the separated ends of the curved plates, and a third .pair of bafiieplates extending parallelto thefsecond pair of baffle plates andarranged be- .tween these baffle plates and the corresponding walls of the body."

4. A device of the class described comprising in combination a tubular portion adapted to communicate with a chimney, a second tubular portion ada ted to communicate with a fire chamber a furnace, a body arranged between said two tubular portions, a wedge shaped deflecting body arranged in said first named body and the apex of which points toward the first mentioned tubular portion and is on a diameter thereof, a second wedge shaped deflecting body arranged in the first named body and pointing into the opposite direction of the first named wedge shaped body, and a pair of exit channels connecting with the first named body and arranged laterally of said second tubular portion.

5. A device of the class described comprising in combination a tubular portion adapted to communicate with a chimney, a second tubular portion adapted to communicate with a fire chamber of a furnace, a body arranged between said tubular portions and communicating with the same, a pair of exit channels arranged laterally of said second tubular portion and communicating with said body, a deflector body arranged inside the first named body and having the general outline of a diamond, two opposite edges of said de flector body being on a diameter of the first and second tubular portion respectively.

In witness whereof I afiix my signature.

KARL BOHN. 

